Overview of a Robust Software Gravitational Wave Simulation Generator A Stuver, L S Finn Center for Gravitational Wave Physics, The Pennsylvania State University, UniversityPark,PA16802,USA E-mail: stuver@gravity.psu.edu Abstract. Physically motivated gravitational wave signals are needed in order to study the behavior and efficacy of different data analysis methods seeking their detection. GravEn, short for Grav itational-wave En gine, is a robust software gravitational wave simulation generator developed in the MATLAB r  programming environment; however, the theory expounded upon in this work can be used in any programming environment. Every aspect of a desired signal can be specified, such as start time of the simulation (including inter-sample start times), maximum strain, source orientation to line-of-sight, location of the source on the sky, etc. Signals can either be generated from the supported built-in waveforms or pre-generated waveforms can be substituted. Supported interferometer detectors include LIGO, GEO, VIRGO and TAMA. Together, these features allow for the generation of coincident (within time- of-flight of a gravitational wave between detectors), meaningful gravitational wave simulations for multiple detectors. This work documents the theory an infrastructure of GravEn as a robust gravitationalwavesimulationgenerator. 1. Introduction In order to adequately test the behavior and efficacies of gravitational wave data analysis methods, a simulation package that mimics expected signals must be developed. To that end, GravEn (Grav itational-wave En gine) simulates gravitational wave signals that can be added into the data stream of a gravitational wave detector. GravEn has been developed in the MATLAB r  programming environment, however, the theory and infrastructure described in this work can be used in any programming language. The source code for this simulation package is available for download from [1] and full operational documentation can be found in [2]. Previously within LIGO, simulations were generated with ad hoc generic mathematical functions, such as Gaussian modulated sinusoids, and these waveforms were considered as the final strain as seen by the detector. GravEn allows the specification of a sources orientation to the line-of-sight of a detector in an arbitrary gauge, projection onto the transverse-traceless (TT) gauge, polarization, and sky